Question

3. What is the concentration of all species at equilibrium for a saturated solution or Ag3AS04 given that the Ksp for this salt is 1.03 x 10-22? What is the concentration of all species at equilibrium for the same salt in a solution that already has a concentration of silver ions of 0.1 M?

Answer 1

#a) Ksp for AgzAsO4 = [Ag+][As04-'] = 1.03 x 10-22 Let S be the solubility of AgzAsO.. AgzAsO4 — 3 Ag+ + As0,-3 solid 35s Ky =(39)' (S) =1.03 <10-22 2754 =1.03 x10-22 S4 = 3.81x10-24 S=1.40x106 Molar solubility = 1.40x10M [Ag+] = 3S = 3 * 1.40 x 10-6 = 4.19 x 10-6 M [AsO4-3) = S = 1.40 x 10-6 M.

#b) Ksp for AgzAsO4 = [Ag+]3[AsO2-3) = 1.03 x 10-22 Let S be the solubility of AgzAsO4. Given that conc. of Ag+ = 0.1 M. So the total conc. of Ag+ ions in the solution = (35 + 0.1)M AgzAsO4 = 3 Ag* + As04-3 solid (35 +0.1) s K., =(3S+0.1)' (S)=1.03 x 10-22 S is small, So, 3S +0.1=0.1 (0.1)' (S)=1.03 <10-22 S=1.03 x 10-19 S=1.03 x10-19 [Ag+] = 35 +0.1 = 0.1 M [AsO4-3) = S = 1.03 x 10-19 M